Sabine FBX2020-Plus Dual Feedback Exterminator Dual-channel, 20-bit digital filtering device that gives you automatic real-time feedback control and increases the clarity and volume of your system. The FBX2020-Plus automatically senses feedback in a sound system and determines its pitch. It then places one of 12 constant "Q" micro-filters on the resonating frequency and eliminates the feedback in typically less than one second. Special features of the FBX2020-Plus: The FBX2020-Plus is a dual-channel unit with an improved algorithm that allows it to better distinguish the difference between feedback and music. It has improved 20-bit digital resolution, providing superior dynamic range and signal-to-noise ratio. The FBX2020-Plus has 12 feedback filters per channel, giving the unit more feedback elimination power for the toughest venues. The FBX2020-Plus's ClipGuard® adaptive clip level control, with TURBO set-up mode, increases the effective dynamic range by more than 10dB and makes set-up faster and easier. The FBX2020-Plus now includes a Dynamic Filter Reset option. The FBX2020-Plus incorporates an internal power supply. Standard FBX features such as lockable fixed filters and switchable 1/10- and 1/5-octave constant "Q" filters are also included.This is a Used unit. It has been tested, cleaned, and reboxed. Operation manual included. 30 Day Warrenty.